Cleaver, 51, takes on the new role at a rough time for De Beers, as diamond prices and sales declined sharply last year amid an economic slowdown in China.

Cleaver, 51, takes on the new role at a rough time for De Beers, the world’s biggest diamond producer, as gem prices and sales declined sharply last year amid an economic slowdown in China, where blooming wealth once fuelled demand for diamonds.

"Having steered through some of the diamond industry's toughest times and with the market showing signs of recovery, now is the right time for me to pass the baton to the next generation," France-born Mellier said in the statement.

Diamonds accounted for 31% of Anglo’s underlying earnings last year, making it the group’s second-most important earnings driver after coal. The company owns 85% of DeBeers.

Cleaver first joined De Beers' board in 2008 and served as its co-acting CEO in 2010 before Mellier's appointment. He will assume on July 1.